Great minds, JOG... great minds, think alike...
...
... ('course,... so do retarded sheep)...
...so that's a wash...
...
But,.. we're simpatico... either way...
...
A. Most basic tests
B. Most simplest/cheapest solution
C. Then,... if it ain't the easy stuff,.. feel safe in moving on...
... but, never go deep, 'till you've scanned the surface...
Nothing makes you feel lower,.. than, seeking a big solution, to a little problem...
(I learned my lesson on my first Metro... when I tried everything to get her started, and found no compression, and decided she needed a new motor... Then, without even looking, my backyard mechanic buddy, told me I'd been trying so hard, for so long, that I had washed the cylinders of their oil compression seal with raw gas, and lost compression... He oiled cylinders and cleared a small bug from the throttle body... and she ran perfect)... He charged me $20 for about 15 minutes.... I gave him $40....
Not my first time,... but the one that taught me my lesson...
Point is,.. a tiny bug made think I needed a new motor....
Excuse my rambling... it's not always the simple thing,... but often as not...
Best luck, Zeke... keep us apprised...